dsh-model-auto-hot-switch: DeepSeek Harness Automatic Model Hot Switching Plugin

`dsh-model-auto-hot-switch` is a DeepSeek Harness (DSH) plugin designed to address the pain point of model switching when mixing multimodal tasks. It locally detects whether a task step contains images and automatically routes such tasks to a vision-capable model, while keeping other tasks on the default model, achieving automatic hot switching with zero additional token consumption and no context interference. Users can enable it with one click via a floating button in the web interface or a configuration file, without relying on the official runtime, making it suitable for efficiently handling mixed text-and-image tasks within a single session.